Schistosoma haematobium is the major cause of parasite induced kidney and bladder damage in endemic areas. Elements contributing to the degree of pathology have been attributed to intensity of infection (worm load), host immune response including cytotoxic T-lymphocyte response, and age of the host. However not all pathological outcomes can be attributed to these phenomena and variation of the parasite itself may play a role. In a collaborative study with colleagues from the Blair Research Institute in Zimbabwe we have the opportunity to obtain preliminary data to examine genetic diversity of S. haematobium infections to see if local genetic differences exist between parasite populations and if these differences include genes affecting virulence. This will be done in young adults using RAPD primers on cercariae derived from single miracidium infections (i.e. from individual worms) in a paired case control study. We will identify two study populations from geographically separate parts of a well researched area, obtain ultrasound data of kidney pathology and epidemiological data, select matched controls and obtain parasite material for RAPD amplification using PCR. Fragments will be scored for presence and absence of common bands and analysed for similarity and percent match. Dendrograms prepared from such data will show any genetic associations. The outcome would provide information on the genetic heterogeneity of this schistosome parasite as well as an indication of worm load and whether there may be a genetic element in the development of pathology induced by the parasite.